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A REVIEW OF IRON SULFIDES AND OXIDES IN COAL MINE WASTE, HUFF RUN WATERSHED, OHIOBurkey, Michael F. 11 May 2018 (has links)
No description available.
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Thermodynamics and Kinetics of Hydrogen Sulfide Corrosion of Mild Steel at Elevated TemperaturesGao, Shujun 01 October 2018 (has links)
No description available.
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Erarbeitung einer Methodik zur Reduzierung der Sauerwasserbildung durch gezielte Abraumverkippung unter Beachtung geogener Potentiale / Development of a methodology for reducing acid water formation through specific overburden tilting under consideration of geogenic potentialsSimon, André 05 April 2016 (has links) (PDF)
Mit dem Grundwasserwiederanstieg in Braunkohleabraumkippen werden die aus der Pyritverwitterung resultierenden Stoffausträge an Sulfat-, Eisen-, Schwermetall- und H+-Ionen gelöst. Im Rahmen dieser Dissertation wurde eine Methodik entwickelt, mit deren Hilfe Problembereiche ausgehalten und somit Maßnahmen im aktiven mitteldeutschen Tagebaubetrieb ergriffen werden können, um die zukünftige Beeinflussung der umgebenden Grund- und Oberflächenwasserkörper zu minimieren. An Vorfeldsedimenten konnten in Feld-eluaten, Stoßbeprobungen und Verwitterungsversuchen geochemische Eigenschaften ermittelt werden. In resultierenden Pufferungsversuchen aus karbonathaltigen Geschiebe-mergeln und Hauptaciditätsträgern konnte eine langfristige Minderung der Aciditätswirkung nachgewiesen werden und ein adaptierter Regelkippenaufbau mit laminaren, alterierenden Sichtaufbau begründet werden. In umliegenden Altkippengrundwässern sind Pufferung und Sulfatreduktion als Wiederfestlegungsprozesse der AMD-Problemstoffe belegt worden. / For lignite mining extensive overburden masses have to be moved. Due to the ventilation of the overburden by atmospheric oxygen, there is a weathering of mostly tertiary sulfides. The rebound of groundwater in future tippings dissolves sulfate, iron, heavy metal and H+ ions, resulting from the pyrite weathering. The partial mobilization of overburden sulfides are opposed to hydrogeochemical buffer reactions e.g. the buffering by carbonates as the first step of buffering.
Therefore, there are the questions to the mining operators of the measures that can be taken to minimize the geochemical influence of the surrounding ground and surface water bodies.
Object of this PhD-thesis is to lead a methodology that helps to characterize the future tilting substrates to find technological and strategic measures for minimizing the acid water formation in the active open pit operation.
In Field eluates and weathering tests in the laboratory and in the field, sediments from dry drill holes in the forefront of open pits “Schleenhain” and “Peres” it could be shown that the geological facies formation of sediments has a decisive influence on geochemical characteristics.
As the main acidifying sediment the tertiary aquifer number 2 (lying part) and number 3 can be identified with their high sulfur contents. With increasing time of oxygen exposure sulfate, iron, heavy metal and H + ions released massively. Furthermore, it appears that carbonate buffer essentially are available as glacial till only in cohesive Quaternary.
With the resulting buffering experiments from glacial till and the most acidic aquifer sediments a long-term retention of iron, heavy metal and H + - ion and a reduction of sulfate release can be shown, if there is a share of at least 40% glacial till to the lying aquifer number 2 sediments or 20% glacial till to the aquifer number 3.
The groundwater quality monitoring of unstructured resaturated old dumps near to the active open pits is comparable to a field test. In addition to weathering zones with high levels of pollutants in the presence of carbonates, buffering processes and sulfate reduction with precipitation of problematic substances in secondary mineral phases can be detected.
Blending the research results of geological and geochemical data, an important, in principle selectively recoverable, buffer potential already exists. The determined mixing ratio from 80-60 mass-% acidic sediments to 20-40 mass-% buffering sediment from the buffering experiments can be realized in tilting. In the open pit “Schleenhain” the missing buffering material can be compensated by mass offset from the open pit “Peres”. With the use of the already existing equipment, it is possible to establish a laminar, alternately tipping body with good geochemical and geotechnical conditions.
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Specifické vlastnosti vody jezer vzniklých po těžbě nerostných surovin v ČR / Specific water properties of pit lakes in the Czech RepublicHrdinka, Tomáš January 2012 (has links)
Anthropogenic lakes constitute a significant part of the Czech countryside water component which has not been given sufficient attention so far. The presented thesis deals with the assessment of variability of physico-chemical properties of water in 30 selected pit lakes in order to identify specific features associated with quarrying of different mineral raw materials, basin morphometry and trophic level of the lakes affecting the quality of accumulated water. In the second part of the thesis the author deals with the comprehensive limnological study of the Hromnické Lake with extreme water chemism resulting from excavation of pyritic shales and focuses on the phenomenon of meromixis especially. The results are based on the evaluation of physical properties of water in the lake vertical profile (temperature, conductivity, dissolved oxygen, pH, transparency and colour) and chemical analyzes of water samples collected from the surface and bottom of the lakes during the four seasons in 2003-07 (determination of Ca, Mg, Na, K, Nammon., NO3 - , SO4 2- , Cl- and alkalinity), including determination of chlorophyll-a. In the case study of the Hromnické Lake conducted in 2010-11, the analysis of hydrological regime of the lake, determination of PO4 3- , TOC, selected metals (Fe, Mn, Al, Zn, Ni, Cu, Co,...
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Tafonomia de grupos fósseis do membro crato (Formação Santana, Bacia do Araripe, Eocretáceo, NE do Brasil): implicações geobiológicas, paleoecológicas e paleoambientais / Taphonomy of fossil groups from the crato member (Santana Formation), Araripe Basin, Early Cretaceous, North-east Brasil): geobiological, palaeoecological, and palaeoenvironmental implicationsOsés, Gabriel Ladeira 27 October 2016 (has links)
Nas últimas décadas, os Lagerstätten estiveram no centro das discussões relativas à história paleobiológica e geológica da Terra. Em particular, o Membro Crato da Formação Santana (Bacia do Araripe, Nordeste do Brasil) é um dos mais significantes Lagerstätten do Cretáceo já que registra invertebrados, vertebrados e plantas excepcionalmente preservados em sedimentos carbonáticos de um palaeolago. O principal objetivo desta dissertação é lançar luz sobre os processos de preservação responsáveis pela fossilização de insetos e peixes com tecidos moles em 3D. Lâminas petrográficas e diversas técnicas paleométricas - micro-Espectroscopia Raman, Fluorescência de raios-X (FRX) convencional, micro-FRX com fonte de luz sincrotron (RS-µFRX), emissão de Raios-X induzida por partículas (PIXE), microscopia eletrônica de varredura (MEV) e espectroscopia de energia dispersiva de Raios-X (EDS) - foram empregadas para caracterizar a rocha matriz, a morfologia e fidelidade de preservação dos tecidos moles e as composições elementares e moleculares dos fósseis em escala de centímetros e mícron. Os resultados revelam que, enquanto insetos e tecidos moles de peixes encontrados nos denominados calcários beges (BL) são substituídos por pseudomorfos de pirita framboidal (após oxidação da pirita), os quais ocorrem juntamente com possíveis substâncias poliméricas extracelulares secretadas por bactérias (EPS), tecidos de peixes dos calcários cinza (GL) são querogenizados. Em insetos, existe variação de tamanho dos framboides para dentro dos fósseis, que é aqui interpretada como produto do equilíbrio entre as taxas de difusão e de nucleação dos minerais. Além disso, a distribuição preferencial de Zn e Cu em estruturas piritizadas de insetos e peixes em comparação com a sua matriz é aqui considerada como sendo o resultado da fixação de elementos químicos em biofilmes bacterianos. Zn concentrado nos ossos de peixes com querogenizados e Fe/Cu observados em seus tecidos moles são considerados como tendo sido incorporados durante a vida dos peixes. No caso particular de peixes, modelo originalmente proposto para a preservação de metazoários do Pré-cambriano é aqui aplicado para explicar a variação de fossilização entre as fácies BL e GL. Lâminas petrográficas revelam que os GL têm geralmente teor de argila/matéria orgânica maior do que os BL, implicando que as taxas de soterramento poderiam ter sido mais intensas nos GL. Isto teria colocado carcaças em decomposição mais rapidamente na zona sedimentar de metanogênese, sendo formado o querogênio. Por outro lado, carcaças depositadas na fácies BL poderiam ter passado período mais longo na zona de redução de sulfato, o que teria levado à piritização generalizada. Além disso, a baixa porosidade do microespato, o cimento e a argila poderiam ter diminuído a migração de aceptores de elétrons dos processos de respiração bacteriana anaeróbia - particularmente redução de sulfato (RS) e metanogênese - e de seus produtos biogeoquímicos, estreitando a zona de RS, o que teria reduzido a influência da piritização em alguns níveis. Enquanto que a piritização resultou na preservação de fibras musculares em 3D, sarcolema, possíveis núcleos celulares, tendões e olhos, a querogenização preservou tecidos conjuntivos, tegumento e fibras musculares distorcidas e compactadas. Em conclusão, é aqui proposto que fácies influenciadas por processos paleoambientais e geobiológicos produziram fósseis com gradiente diferencial de fidelidade de preservação de acordo com cada via tafonômica seguida. / Over the past decades, the so-called Fossil Lagerstätten have been in the core of discussions concerning the palaeobiological and geological history of the Earth. In particular, the Crato Member from the Santana Formation (Araripe Basin, north-east Brazil) is one of the most significant Cretaceous Lagerstätten since it records exceptionally well-preserved fossil invertebrates, vertebrates, and plants, deposited in palaeolake carbonate beds. The main aim of this dissertation is to shed light on the preservational processes responsible for the fossilization of insects and fishes still retaining 3D soft tissues. Petrographic thin sections and several palaeometric techniques - micro-Raman Spectroscopy, conventional X-ray Fluorescence (XRF), Synchrotron micro-XRF (SR-µXRF), Particle-Induced X-ray Emission (PIXE), Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray Spectroscopy (EDS) - have been employed to characterize the host rock, soft-tissue morphology and preservational fidelity, and fossil elemental and molecular compositions in centimetre to micrometre scale. The results reveal that while insects and fish soft-tissues found in the so called beige limestones (BL) are replaced by framboidal pyrite pseudomorphs (after pyrite oxidation) occurring together with putative bacterially-secreted extracellular polymeric substances (EPS), labile tissues of fishes from the grey limestones (GL) are kerogenized. In insects, there is a variation of framboid size inward the fossils, which is here interpreted as a product of the balance between diffusion and mineral nucleation rates. Moreover, the preferential distribution of Zn and Cu in pyritized insect/fish labile structures in comparison to their rock matrix is here considered as being the result of element fixation in bacterial biofilms. Zn concentrated in bones of kerogenized fishes and Fe/Cu occurring in their soft tissues are considered to have been incorporated during fish life. In the particular case of fishes, a model originally proposed for metazoan preservation in the Precambrian is here applied to explain the variation of fossilization between the BL and GL facies. Petrographic thin sections reveal that GL have generally higher clay/organic matter contents than BL, thus implying that burial rates might have been more intense in the former. This could have placed decaying carcasses more quickly in the methanogenesis sedimentary zone, in that way being kerogenized. On the other hand, carcasses deposited in the BL facies could have spent a longer period in the sulphate-reduction zone, which would have accounted for pervasive pyritization. Additionally, microspar low porosity, cement and clay could have diminished both downward migrations of electron acceptors for anaerobic bacterial respiration processes - particularly sulphate-reduction (SR) and methanogenesis - and of their biogeochemical products, narrowing the SR zone, which would have lowered the impact of pyritization in some levels. While pyritization has recorded 3D muscle fibres, sarcolemma, putative cell nuclei, tendons and eyes, kerogenization has yielded connective tissues, integument and compressed/distorted muscle fibres. In conclusion, it is here proposed that palaeoenvironmental/geobiological-influenced facies have yielded fossils with a variable preservational-fidelity gradient, accordingly to each taphonomic pathway followed.
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Malmmineralogisk undersökning av Pb-, Zn-, Cu- och Ag-förande kvartsgångar i Värmskogsområdet, mellersta VärmlandNysten, Christina January 2013 (has links)
Abstract Polymetallic (Pb-Zn-Cu-Ag-Au-Sb-As-Bi-Cd-Te-Se-Ge…) quartz veins occur in an area from Eidsvoll in southeastern Norway to west of LakeVänern in southwestern Sweden. They most likely formed during the waning stage of the c. 1 Ga Sveconorwegian orogeny. In Värmskog parish, Värmland county, several mineralized quartz veins of different types are known. Of these, three of the larger vein deposits, Vegerbol, Karlsbol and Södra Gärdsjön, have been investigated. Despite a history of mining activities (mostly for silver) and exploration from the mid-1800s up until the present day, details about their ore mineralogy have remained essentially unknown. In order to classify and characterize them better, the present study was undertaken. The main ore minerals in the veins are galena, sphalerite, chalcopyrite, tetrahedrite sensu lato and pyrite. Additionally, this investigation showed the occurrence of an array of silver-bearing phases such as argentian tetrahedrite to freibergite, native silver, polybasite, pyrargyrite, jalpaite, aguilarite, cervelleite, hessite and matildite. These are the main and accessory silver carriers in the studied deposits. Gold (argentiferous) was also found, as well as the nickel-cobalt sulphide siegenite. The silver contents of the tetrahedrites may vary within one deposit, ranging from tetrahedrite sensu stricto to freibergite. A weak positive correlation occurs between silver and iron in the tetrahedrites. Cadmium was found both in the tetrahedrites and in the sphalerites. Many sphalerites, however, are very pure ZnS. The complex accessory ore mineralogy, including native gold as well as tellurium and selenium-bearing phases (Vegerbol), makes these vein deposits comparable to mineralized veins to the west and southwest of the Värmskog area. Combining mineralogical and textural observations with previous studies, the vein mineralizations most likely formed during a change in tectonic regime, in recurrently active brittle structures, at temperatures ranging from c. 350 down to below 100°C. The occurrence of pyrite and hematite and the lack of pyrrhotite and magnetite points to an oxidizing ore-forming environment with relatively high sulphur activity. Finally, in order to assess the possibility of connecting two of the mined vein systems, VLF (Very Low Frequency) electromagnetic measurements were performed across the strike of a possible continuation between the Vegerbol and Karlsbol deposits. The VLF survey showed a significant anomaly where such a continuation was to be expected, thus indicating an overall strike length of at least 1 km for that vein system. / Sammanfattning Polymetalliska (Pb-Zn-Cu-Ag-Au-Sb-As-Bi-Cd-Te-Se-Ge…) kvartsgångar förekommer inom ett område från Eidsvoll, Norge i norr, till sydväst om Vänern i Sverige. De tros ha bildats under den svekonorvegiska orogenesens (ca 1 Ga) slutskede. I Värmskogs socken, Värmland, förekommer mineraliserade kvartsgångar av flera olika typer. Bland dessa har tre undersökts med avseende på malmmineralogi. Dessa kallas för Vegerbol, Karlsbol och Södra Gärdsjön, och de har brutits i huvudsak på silver. Trots att brytning och prospekteringsarbeten pågått från 1800-talet fram till i dag har det saknats detaljerade mineralogiska beskrivningar över fyndigheterna. Denna studie har genomförts för att bättre kunna karakterisera och klassificera dessa mineraliseringar. Huvudmalmmineral vid dessa förekomster är blyglans, zinkblände, kopparkis, pyrit och för Södra Gärdsjön även tetraedrit. Denna undersökning har påvisat förekomsten av silverförande faser som silverhaltig tetraedrit till freibergit, gediget silver, polybasit, jalpait, aguilarit, cervelleit, hessit och matildit, vilka utgör både huvudsakliga och accessoriska silverbärare i de undersökta förekomsterna. Guld (silverhaltigt) har också hittats, samt ett Ni-Co-förande mineral, siegenit. Silverinnehållet i tetraedriterna varierar inom en och samma förekomst, några analyser har givit freibergitsammansättningar. En svag positiv korrelation finns mellan silver och järnhalt i tetraedrit. Kadmium förekommer både i tetraedrit och i zinkblände. Många zinkbländen består dock av rent ZnS. Förekomsten av relativt komplexa accessoriska mineral inklusive guld och Se-Te-faser (Vegerbol) visar att dessa gångar är jämförbara med liknande förekomster väster och sydväst om Värmskogsområdet. Genom att sammanföra data från denna undersökning med sådana från tidigare studier gjorda på gångarna kan man anta att de bildats vid vid en förändring av den tektoniska miljön, i upprepat aktiva spröda strukturer och vid temperaturer mellan ungefär 350 till under 100 °C. Förekomsten av pyrit och hematit samt avsaknad av magnetkis och magnetit tyder på att malmbildningen skett under oxiderade förhållanden och relativt hög svavelaktivitet. Elektromagnetiska mätningar i VLF-bandet (Very Low Frequency) utfördes tvärs över den förmodade strykningsriktningen för en möjlig fortsättning av gången mellan Karlsbol och Vegerbol. Mätningarna gav en tydlig anomali där en sådan fortsättning kan förväntas vilket skulle kunna betyda att det finns en sammanhängande mineralisering med ca 1 kilometers längd.
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Climate and sea level variations in the Gulf of Lion : coupling stable and radiogenic isotopes proxies / Variations climatiques et glacio-eustatiques dans le Golfe du Lion : une approche couplée des isotopes stables et radiogéniquesPasquier, Virgil 17 November 2017 (has links)
De par sa position, le Golfe du Lion est un site idéal pour l’investigation des changements paléo-environnementaux et des processus affectant le dépôt sédimentaire. Les travaux antérieurs ont permis de mettre en évidence les impacts de la variabilité climatique et glacioeustatique sur l’organisation stratigraphique de la marge, mais également sur les exports terrestres de matière organique.L’étude isotopique du carbone organique et de l’azote de la matière organique dans les sédiments du forage PRGL1-4 nous a permis de mettre en évidence de forts exports fluviaux lors des interstades survenus au cours des 200 000 derniers milles ans. La mise en regard de cette découverte avec les enregistrements paléo-climatologiques terrestre et marin disponibles dans la région indique que ces forts exports fluviaux résultent d’une augmentation des précipitations le long de la bordure Nord Méditerranéenne. Grâce à la position dePRGL1-4, nous proposons que ces pluies soient le résultat d’une augmentation du passage de dépressions Nord Atlantique dans le bassin Ouest Méditerranéen.Une caractérisation des isotopes du soufre préservés dans la pyrite sédimentaire a été réalisée. Les résultats obtenus ont permis de mettre en évidence une variation isotopique insoupçonnée, l’une des plus grandes observées de nos jours, dont la cyclicité semble indiquer un fort contrôle climatique. Nous proposons deux mécanismes influençant le fractionnement isotopique: une modulation de l’activité bactérienne par le climat, et/ou (ii) une modulation locale liée la nature des sédiments impliqués dans la formation des pyrites en lien avec les variations eustatiques. / By its position, the Gulf of Lion is an ideal location for investigation of past ecological changes and processes affecting the sedimentary deposition. Previous work has highlighted the impacts of climatic and glacio-eustatic changes on the GoL stratigraphic organization, but also on terrestrial exports of organic matter.This isotopic study based on the organic carbon and nitrogen preserved in PRGL1-4 sediments highlights important rivers runoff during warm periods of the last 200 000 years.Regional intercomparison with terrestrial and marine records indicates that these river exports resulting from an increase of precipitation over the North Mediterranean borderland.Using PRGL1-4 location, out of Mediterranean cyclogenetic area, we suggest that these pluvial events occurred in response to enhance passage of North Atlantic atmospheric perturbation into the Western Mediterranean basin.Pyrite sulfur isotopes investigations over the last 500 kyr have also been done. The stratigraphic variations (up to 76‰) in the isotopic data reported here are among the largest ever observed in pyrite, and are in phase with glacial-interglacial sea level. These results suggest that there exist important but previously overlooked depositional controls on sedimentary sulfur isotope records. Two different mechanisms influencing the isotopic fractionation can explain the observed dataset: a climatic modulation of the bacterial activity, and / or (ii) a local sedimentary modulation involve during early diagenetic formation of pyrite in relation with the eustatic variations.
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Genetic relationships and origin of the Ädelfors gold deposits in Southeastern SwedenWiberg Steen, Tobias January 2018 (has links)
Ädelfors is situated ca 17 km east of Vetlanda, Jönköping County, in the N-S striking Trans-scandinavian igneous belt and is a part of the NE-SW striking 1.83-1.82 Ga Oskarshamn-Jönköping belt emplaced during a continental subduction towards the Svecofennian continental margin. The continental arc hosts the 1.83 Ga metasedimentary Vetlanda supergroup composed of foliated metagreywacke, metasandstone and metaconglomerate. The sequence is intercalated by mafic and felsic volcanites and hosts the Cu-Au-Fe-mines at Ädelfors. Ädelfors mining field consists of ca 330 mineralized quartz veins hosting both copper, gold and iron. The iron mines Nilsson’s iron mine (NFE) and Fe-mine (FE), the copper mine Kamelen (KM) and the gold mines Brånad’s mine (BR), Adolf Fredrik’s mine (AF), Old Kron mine (GKR), Old Kolhag’s mine (GKO), Thörn mine (TH), New Galon mine (NG), Stenborg’s mine (ST), Tysk mine (TG), Hällaskallen (HS) and Fridhem (FR) have been investigated to deduce a possible genetic relation between the veins and their origin. Sulfur isotope ratios have also been conducted on pyrite from KM, AF and FE. The veins can stucturally be divided into several groups. AF, GKR, ST, NG, TH and possibly NFE are striking 10-70° with a dip of 55-70°. BR, GKO and KM are striking 110-140° with a dip of 80-90° whereas TG and HS strike 90-110° dipping 85°. Fridhem, being distal to the other mines, strikes 70° and dips 80°. A chlorite-quartz-biotite-sericite-rich metapelite hosts the veins in all localities except; FR where a layered, beresitizised felsic volcanite rich in plagioclase, sericite, biotite and quartz hosts disseminated pyrite; and NFE, HS and NG which are hosted by a mafic tuffite. Quartz veins are mainly milky and equigranular, exceptions are FE with black pyrite-bearing quartz veins, cutting through the banded magnetite-metapelite and KM with its dynamically recrystallized quartz. Chlorite-, zeolite-, carbonate-, hematite-, amphibole-, kalifeldspar-, sericite-, biotite- and epidote alteration has been observed among the localities. The ore minerals are dominated by: fractured sub- to euhedral pyrite in cataclastic aggregates or selvage bands, interstitial chalcopyrite in pyrite, marcasite, pyrrhotite, gold and sporadic chalcopyrite diseased sphalerite and arsenopyrite. Previously not reported tetradymite, staurolite, galena and Ce-monazite have also been observed. Bismuthinite and tetradymite as inclusions in pyrite were observed in AF, GKR, FR and TG. Gold was observed in AF, BR, GKR and TG as inclusions in pyrite or quartz with a Au/Ag median of 78.41. HS distinguishes itself with Au/Ag ratios of 4.66-5.25. The trace element ratios in pyrite reveal two major types of pyrite. 1) found in FE and KM (pyrite type 1) with Co/Ni ratio of 10.94, Bi/Au of 1.79, Bi/S of 0.037, Au/Ag of 11.13, S/Se of 235.96 and As/S of 0.006. 2) found in NG, GKO, ST, TH, AF, NFE, HS, GKR, BR, FR, TG and as stringers in KM4 py1 pyrite type 2) with an average Co/Ni ratio of 5.26, Bi/Au of 1.95, Bi/S of 0.031, Au/Ag of 4.19, S/Se of 0 and As/S of 0. δ34S values strengthens this grouping as KM and FE has 1,3-2,6 ‰ and AF 3,6-3,8 ‰. The following geological interpretation has been concluded: The banded iron formation in FE is the earliest mineralization and was later fractured, emplacing quartz veins with pyrite of type 1. During this event, the Cu-vein in KM was also formed. A second generation of fractures, emplaced after the Småland granitoids formed, were filled with quartz and pyrite of type 2 at mesozonal depth. This is the main stage of gold mineralization and includes NG, GKO, ST, TH, AF, NFE, GKR, BR, FR and TG. During this event, pyrite of type 2 was added to KM, causing recrystallizing of the quartz. HS is possibly emplaced last or altered as it is more enriched in silver. Morphology, mineralogy, alterations, mineral chemistry and sulfur isotope signatures indicates an orogenic origin of the gold-rich quartz veins at Ädelfors as well as the copper-rich vein in KM. / Ädelfors ligger ca 17 km öster om Vetlanda, Jönköpings län, i det N-S strykande Transskandinaviska granit och porfyrbältet och är en del av det NÖ-SV strykande 1,83-1,82 Ga Oskarshamn-Jönköpingsbältet (OJB) bildad i en kontinental subduktionszon i kanten av den Svecofenniska kontinentalplattan. I denna kontinentalbåge ligger Vetlanda supergruppen som är en metasedimentär del av OJB bestående av starkt folierad 1,83 Ga metagråvacka, metasandsten och metakonglomerat med inlagringar av mafiska och felsiska vulkaniter. Ädelfors gruvfält består utav ca. 330 kvartsgångar förande mestadels guld men också koppar. Järnmineraliseringar i form av bandad järnmalm finns också i området. Geologin, mineralogin och pyritens kemiska sammansättning från järngruvorna Nilssons järngruva (NFE) och Fe-gruvan (FE), koppargruvan Kamelen (KM) och guldgruvorna Brånadsgruvan (BR), Adolf Fredriks gruva (AF), Gamla Krongruvan (GKR), Gamla Kolhagsgruvan (GKO), Thörngruvan (TH), Nya Galongruvan (NG), Stenborgs gruva (ST), Tyskgruvan (TG), Hällaskallen (HS) och Fridhem (FR) har undersökts för att finna eventuella genetiska likheter. Svavelisotopförhållande har fastställts för pyrit från AF, FE och KM. Strukturellt kan gångarna delas in i ett antal grupper. AF, GKR, ST, NG, TH och möjligtvis NFE stryker 10-70° och stupar 55-70°. BR, GKO och KM stryker 110-140° och stupar 80-90° medan TG och HS stryker 90-110° och stupar 85°. Fridhem stryker 70° och stupar 80°. En klorit-kvarts-sericit-biotitrik metapelit utgör värdbergarten i alla gruvor förutom; FR där den utgörs av en beresitiserad felsisk vulkanit rik på plagioklas, sericit, biotit och kvarts med disseminerad pyrit; och NFE, HS, NG vilka har en mafisk tuffitisk moderbergart. Kvartsgångarna är mjölkvita med undantag för FE:s svarta, pyritförande kvarts vilket uppträder som sprickfyllnad i den bandade järnmalmen och är senare bildad. Kvartsen i KM är starkt dynamiskt omkristalliserad. Svag till måttlig foliation är vanlig i sidoberget med undantag av stark foliation i TG och NFE, vilka är lokaliserade i förkastningssprickor med stark kloritförskiffring av värdbergarten. Klorit-, zeolit-, karbonat-, hematit-, amfibol-, kalifältspat-, sericit-, biotit- och epidotomvandling förekommer i majoriteten av lokalerna. Malmmineralen är dominerande sprött deformerad subhedral till euhedral pyrit som kataklastiska aggregat eller band, interstitiell kopparkis i pyrit, markasit, magnetkis, guld och sporadiskt kopparkissjuk zinkblände och arsenikkis. I det här arbetet har även tetradymit, staurolit, blyglans och Ce-monazit observerats. Bismutinit och tetradymit i form av inneslutningar i pyrit observerades i AF, GKR, FR och TG. Guld observerades i AF, BR, GKR och TG som inneslutningar i pyrit eller fritt i kvarts med Au/Ag medianvärde på 78,41, avvikande är HS med värden mellan 4,66-5,25. Förhållanden mellan spårelement i pyrit indikerar två typer av pyrit. Typ 1 funnen i FE och KM har följande värden: Co/Ni = 10,94, Bi/Au = 1,79, Bi/S = 0,037, Au/Ag = 11,13, S/Se = 235,96 och As/S = 0,006. Typ 2 funnen i NG, GKO, ST, TH, AF, NFE, HS, GKR, BR, FR, TG och som sliror i KM4 py1 har följande värden Co/Ni = 5,26, Bi/Au = 1,95, Bi/S = 0,031, Au/Ag = 4,19, S/Se = 0 and As/S = 0. δ34S värden styrker denna uppdelning där KM och FE har värdena 1,3-2,6 ‰ och AF 3,6-3,8 ‰. Den geologiska utvecklingen av fältet har tolkats som följande: FE-gruvans bandade järnmalm är den tidigaste mineraliseringen vilket följs utav uppsprickning och läkning av kvarts med pyrit typ 1 som också bildar kopparmineraliseringen KM. Senare sprickzoner efter Smålandsgraniternas intrusion läks av kvarts med pyrit typ 2 på mesozonalt djup vilket bildar NG, GKO, ST, TH, AF, NFE, GKR, BR, FR, TG och omkristalliserar och introducerar nya pyritsliror i kvartsen i KM. HS bildas möjligtvis sist eller har blivit omvandlad eftersom den är anrikad på silver. Morfologi, omvandlingar och svavelisotop-signaturer tyder på ett orogent ursprung för Ädelfors guldrika kvartsådror samt den kopparrika kvartsådern i KM.
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Erarbeitung einer Methodik zur Reduzierung der Sauerwasserbildung durch gezielte Abraumverkippung unter Beachtung geogener PotentialeSimon, André 17 December 2015 (has links)
Mit dem Grundwasserwiederanstieg in Braunkohleabraumkippen werden die aus der Pyritverwitterung resultierenden Stoffausträge an Sulfat-, Eisen-, Schwermetall- und H+-Ionen gelöst. Im Rahmen dieser Dissertation wurde eine Methodik entwickelt, mit deren Hilfe Problembereiche ausgehalten und somit Maßnahmen im aktiven mitteldeutschen Tagebaubetrieb ergriffen werden können, um die zukünftige Beeinflussung der umgebenden Grund- und Oberflächenwasserkörper zu minimieren. An Vorfeldsedimenten konnten in Feld-eluaten, Stoßbeprobungen und Verwitterungsversuchen geochemische Eigenschaften ermittelt werden. In resultierenden Pufferungsversuchen aus karbonathaltigen Geschiebe-mergeln und Hauptaciditätsträgern konnte eine langfristige Minderung der Aciditätswirkung nachgewiesen werden und ein adaptierter Regelkippenaufbau mit laminaren, alterierenden Sichtaufbau begründet werden. In umliegenden Altkippengrundwässern sind Pufferung und Sulfatreduktion als Wiederfestlegungsprozesse der AMD-Problemstoffe belegt worden.:Versicherung 3
Zusammenfassung 8
1 Aktualität und Bedeutung der gesteuerten Abraumverkippung 10
2 Theoretische Grundlagen, Ziele, Aufgaben und Technik 15
2.1 Das System Kippe mit Verwitterungsstufen und Stufen der Gegenmaßnahmen 16
2.1.1 Phasen der Tagebauentwicklung in Bezug auf die Sauerwasserbildung 16
2.1.2 Systematik der Gegenmaßnahmen 18
2.2 Pyritbildung, Verwitterung, Pufferung und Wiederfestlegung 22
2.2.1 Pyritbildung 22
2.2.2 Pyritverwitterung 22
2.2.3 Pufferreaktionen 24
2.2.4 Wiederfestlegung durch autochthone mikrobielle Sulfatreduktion 26
2.2.5 Wiederfestlegung durch technisch- biologisch forcierte Sulfatreduktion 28
2.3 Geochemische Verhältnisse der Kippen Zwenkau und Witznitz 30
2.4 Geräteeinsatz im Tagebau des Untersuchungsgebietes 33
3 Ableitung einer Untersuchungsmethodik 35
3.1 Bearbeitungsziel und Ableitung der notwendigen Methoden 35
3.1.1 Geologisches Modell 36
3.1.2 Geochemisches Modell 38
3.1.3 Gewinnungstechnologisches Modell 39
3.2 Vorfeldbohrungen, Korngrößenbestimmung, stoffliche Charakterisierung und RFA 41
3.2.1 Vorfeldbohrungen 41
3.2.2 Lagerung und Probenahme 42
3.2.3 Körnungsanalyse und Wassergehaltsbestimmung 43
3.2.4 Feststoffcharakterisierung Kohlenstoff / Schwefel mittels CS-Mat 44
3.2.5 Röntgenfluoreszenzanalytik 44
3.3 Feldeluate, HCl-Test und organoleptische Ansprache 46
3.3.1 Feldelution 46
3.3.2 Salzsäure-Test (HCl-Test) 47
3.3.3 Organoleptische Ansprache 47
3.3.4 Hydrolytische Acidität 48
3.4 Verwitterungsversuche 49
3.5 Stoßbeprobung 51
3.6 Pufferungsversuche 52
3.7 Kippengrundwassermonitoring 54
3.7.1 Grundwassermessstellen und Probenahmeequipment 54
3.7.2 Feldanalytik 55
3.7.3 Laboranalytik 56
3.7.4 Hydrogeochemische Modellierung 56
4 Grundlagen und geologische Beschreibung des Untersuchungsgebietes 58
4.1 Untersuchungsgebiet 58
4.2 Tertiäre Einheiten 59
4.3 Quartäre Einheiten 61
4.4 Abgrenzung und Festlegung der Auswerteeinheiten 61
4.5 Vorfeldbohrungen 62
5 Anwendung der Methodik für den Tagebau Vereinigtes Schleenhain 65
5.1 Baufeld Schleenhain 65
5.1.1 Vorfeldbohrungen und Feldeluate 65
5.1.2 Stoffliche C/S-Charakterisierung 69
5.1.3 Verwitterungsversuche 72
5.1.4 Stoßbeprobung 85
5.1.5 Pufferungsversuche 90
5.1.6 Körnungsanalyse und Verwitterungszugänglichkeit 99
5.2 Baufeld Peres 103
5.2.1 Feldeluate 103
5.2.2 Vorfeldbohrungen und stoffliche Charakterisierung 105
5.2.3 Verwitterungsversuche 107
5.2.4 Pufferungsversuche 113
5.3 Beschaffenheit der Kippengrundwässer 114
5.3.1 Grundlegende hydrogeochemische Charakterisierung 115
5.3.2 Verwitterungszonen 117
5.3.3 Spurenmetallgehalte 118
5.3.4 Wirksamkeit der geogenen Puffer 119
5.3.5 Kennzeichnung der Sulfatreduktion als natürlicher Rückhalteprozess 121
5.3.6 Hydrochemische Modellierung 124
5.4 Fehlerdiskussion 126
6 Übertragung der Ergebnisse, Bewertung und Schlussfolgerung 127
6.1 Geologisches Modell und technische Verschnittmöglichkeiten 127
6.1.1 Geologisch-genetische Charakteristik der Auswerteeinheiten 127
6.1.2 Verbreitung und Mächtigkeit wesentlicher Auswerteeinheiten im Tagebau „Vereinigtes Schleenhain“ 128
6.1.3 Tagebautechnologische Verschnittmöglichkeiten 130
6.2 Geochemische Möglichkeiten bei der Umstellung der Tagebautechnologie – Massenversatz und Mischung 132
6.2.1 Gewinnungsscheiben 132
6.2.2 Regelkippenaufbau 134
6.2.3 „Schnelle Fahrweise“ und (Zwischen-) Abdeckung 134
6.2.4 Einmischung der Sedimente 135
6.3 RFA-Analytik und Bewertung von Sedimenteigenschaften 137
7 Zusammenfassung und weiterer Handlungsbedarf 139
7.1 Zusammenfassung - Ergebnisse Vorfeldbohrungen 139
7.2 Zusammenfassung – Verwitterungsversuche Labor und Feld 139
7.3 Zusammenfassung – Pufferungsversuche Schleenhain und Peres 141
7.4 Zusammenfassung – Gütemonitoring Kippengrundwässer 141
7.5 Zusammenfassung – Geologisches Modell/ Verschnitt/Technologie 142
7.6 Nachweis der Anwendbarkeit der Methode 144
7.7 Ausblick und weiterer Handlungsbedarf 145
Literatur und Quellen 146
Tabellenverzeichnis 151
Abbildungsverzeichnis 151
Abkürzungsverzeichnis 157
Anlagen 159 / For lignite mining extensive overburden masses have to be moved. Due to the ventilation of the overburden by atmospheric oxygen, there is a weathering of mostly tertiary sulfides. The rebound of groundwater in future tippings dissolves sulfate, iron, heavy metal and H+ ions, resulting from the pyrite weathering. The partial mobilization of overburden sulfides are opposed to hydrogeochemical buffer reactions e.g. the buffering by carbonates as the first step of buffering.
Therefore, there are the questions to the mining operators of the measures that can be taken to minimize the geochemical influence of the surrounding ground and surface water bodies.
Object of this PhD-thesis is to lead a methodology that helps to characterize the future tilting substrates to find technological and strategic measures for minimizing the acid water formation in the active open pit operation.
In Field eluates and weathering tests in the laboratory and in the field, sediments from dry drill holes in the forefront of open pits “Schleenhain” and “Peres” it could be shown that the geological facies formation of sediments has a decisive influence on geochemical characteristics.
As the main acidifying sediment the tertiary aquifer number 2 (lying part) and number 3 can be identified with their high sulfur contents. With increasing time of oxygen exposure sulfate, iron, heavy metal and H + ions released massively. Furthermore, it appears that carbonate buffer essentially are available as glacial till only in cohesive Quaternary.
With the resulting buffering experiments from glacial till and the most acidic aquifer sediments a long-term retention of iron, heavy metal and H + - ion and a reduction of sulfate release can be shown, if there is a share of at least 40% glacial till to the lying aquifer number 2 sediments or 20% glacial till to the aquifer number 3.
The groundwater quality monitoring of unstructured resaturated old dumps near to the active open pits is comparable to a field test. In addition to weathering zones with high levels of pollutants in the presence of carbonates, buffering processes and sulfate reduction with precipitation of problematic substances in secondary mineral phases can be detected.
Blending the research results of geological and geochemical data, an important, in principle selectively recoverable, buffer potential already exists. The determined mixing ratio from 80-60 mass-% acidic sediments to 20-40 mass-% buffering sediment from the buffering experiments can be realized in tilting. In the open pit “Schleenhain” the missing buffering material can be compensated by mass offset from the open pit “Peres”. With the use of the already existing equipment, it is possible to establish a laminar, alternately tipping body with good geochemical and geotechnical conditions.:Versicherung 3
Zusammenfassung 8
1 Aktualität und Bedeutung der gesteuerten Abraumverkippung 10
2 Theoretische Grundlagen, Ziele, Aufgaben und Technik 15
2.1 Das System Kippe mit Verwitterungsstufen und Stufen der Gegenmaßnahmen 16
2.1.1 Phasen der Tagebauentwicklung in Bezug auf die Sauerwasserbildung 16
2.1.2 Systematik der Gegenmaßnahmen 18
2.2 Pyritbildung, Verwitterung, Pufferung und Wiederfestlegung 22
2.2.1 Pyritbildung 22
2.2.2 Pyritverwitterung 22
2.2.3 Pufferreaktionen 24
2.2.4 Wiederfestlegung durch autochthone mikrobielle Sulfatreduktion 26
2.2.5 Wiederfestlegung durch technisch- biologisch forcierte Sulfatreduktion 28
2.3 Geochemische Verhältnisse der Kippen Zwenkau und Witznitz 30
2.4 Geräteeinsatz im Tagebau des Untersuchungsgebietes 33
3 Ableitung einer Untersuchungsmethodik 35
3.1 Bearbeitungsziel und Ableitung der notwendigen Methoden 35
3.1.1 Geologisches Modell 36
3.1.2 Geochemisches Modell 38
3.1.3 Gewinnungstechnologisches Modell 39
3.2 Vorfeldbohrungen, Korngrößenbestimmung, stoffliche Charakterisierung und RFA 41
3.2.1 Vorfeldbohrungen 41
3.2.2 Lagerung und Probenahme 42
3.2.3 Körnungsanalyse und Wassergehaltsbestimmung 43
3.2.4 Feststoffcharakterisierung Kohlenstoff / Schwefel mittels CS-Mat 44
3.2.5 Röntgenfluoreszenzanalytik 44
3.3 Feldeluate, HCl-Test und organoleptische Ansprache 46
3.3.1 Feldelution 46
3.3.2 Salzsäure-Test (HCl-Test) 47
3.3.3 Organoleptische Ansprache 47
3.3.4 Hydrolytische Acidität 48
3.4 Verwitterungsversuche 49
3.5 Stoßbeprobung 51
3.6 Pufferungsversuche 52
3.7 Kippengrundwassermonitoring 54
3.7.1 Grundwassermessstellen und Probenahmeequipment 54
3.7.2 Feldanalytik 55
3.7.3 Laboranalytik 56
3.7.4 Hydrogeochemische Modellierung 56
4 Grundlagen und geologische Beschreibung des Untersuchungsgebietes 58
4.1 Untersuchungsgebiet 58
4.2 Tertiäre Einheiten 59
4.3 Quartäre Einheiten 61
4.4 Abgrenzung und Festlegung der Auswerteeinheiten 61
4.5 Vorfeldbohrungen 62
5 Anwendung der Methodik für den Tagebau Vereinigtes Schleenhain 65
5.1 Baufeld Schleenhain 65
5.1.1 Vorfeldbohrungen und Feldeluate 65
5.1.2 Stoffliche C/S-Charakterisierung 69
5.1.3 Verwitterungsversuche 72
5.1.4 Stoßbeprobung 85
5.1.5 Pufferungsversuche 90
5.1.6 Körnungsanalyse und Verwitterungszugänglichkeit 99
5.2 Baufeld Peres 103
5.2.1 Feldeluate 103
5.2.2 Vorfeldbohrungen und stoffliche Charakterisierung 105
5.2.3 Verwitterungsversuche 107
5.2.4 Pufferungsversuche 113
5.3 Beschaffenheit der Kippengrundwässer 114
5.3.1 Grundlegende hydrogeochemische Charakterisierung 115
5.3.2 Verwitterungszonen 117
5.3.3 Spurenmetallgehalte 118
5.3.4 Wirksamkeit der geogenen Puffer 119
5.3.5 Kennzeichnung der Sulfatreduktion als natürlicher Rückhalteprozess 121
5.3.6 Hydrochemische Modellierung 124
5.4 Fehlerdiskussion 126
6 Übertragung der Ergebnisse, Bewertung und Schlussfolgerung 127
6.1 Geologisches Modell und technische Verschnittmöglichkeiten 127
6.1.1 Geologisch-genetische Charakteristik der Auswerteeinheiten 127
6.1.2 Verbreitung und Mächtigkeit wesentlicher Auswerteeinheiten im Tagebau „Vereinigtes Schleenhain“ 128
6.1.3 Tagebautechnologische Verschnittmöglichkeiten 130
6.2 Geochemische Möglichkeiten bei der Umstellung der Tagebautechnologie – Massenversatz und Mischung 132
6.2.1 Gewinnungsscheiben 132
6.2.2 Regelkippenaufbau 134
6.2.3 „Schnelle Fahrweise“ und (Zwischen-) Abdeckung 134
6.2.4 Einmischung der Sedimente 135
6.3 RFA-Analytik und Bewertung von Sedimenteigenschaften 137
7 Zusammenfassung und weiterer Handlungsbedarf 139
7.1 Zusammenfassung - Ergebnisse Vorfeldbohrungen 139
7.2 Zusammenfassung – Verwitterungsversuche Labor und Feld 139
7.3 Zusammenfassung – Pufferungsversuche Schleenhain und Peres 141
7.4 Zusammenfassung – Gütemonitoring Kippengrundwässer 141
7.5 Zusammenfassung – Geologisches Modell/ Verschnitt/Technologie 142
7.6 Nachweis der Anwendbarkeit der Methode 144
7.7 Ausblick und weiterer Handlungsbedarf 145
Literatur und Quellen 146
Tabellenverzeichnis 151
Abbildungsverzeichnis 151
Abkürzungsverzeichnis 157
Anlagen 159
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